On 03/20/2014 10:05 AM, Faizul Bari wrote:
Hello,
I have been trying to track different phases of a live migration process. I am using libvirt with qemu-kvm. I am issuing migration commands using virsh.
Now, I want to measure the time spent in each phase of live migration, e.g., pre-copy and stop-copy. I stumbled upon the file qemu_driver.c. It has functions like
qemudDomainMigratePrepare2 qemudDomainMigratePerform qemudDomainMigrateFinish2
These functions perform different handshakes between the two libvirt ends of the migration. However, the entire migration is done by a single qemu monitor command, and it is that monitor command that further divides the work into phases such as pre-copy and stop-copy.
I want to know whether qemudDomainMigratePerform and qemudDomainMigrateFinish2 directly map to the pre-copy and stop-copy phase? or the qemudDomainMigratePerform function performs both of them?
The MigratePerform function is the one place that calls the qemu monitor command. I know there have been proposals upstream in qemu to add additional statistics in 'query-migrate' monitor command; perhaps there is still more work needed in libvirt to grab those additional statistics in a manner that can be exposed to the user. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org